1. Field of the Invention
The present invention relates to a cellular radio communication system having base stations constructed in the form of a daisy chain and a method of controlling data transmission using the system. In particular, the present invention relates to a cellular radio communication system having base stations constructed in the form of a daisy chain and a method of controlling data transmission using the system whereby data communications with a plurality of base stations as well as data communications among the respective base stations can be performed using a single base station controller and shared transmission lines in a specified area wherein expressways or railroads are constructed, and wherein the traffic amount is relatively small, but the whole service area is relatively large in comparison to a thickly-populated downtown area.
2. Discussion of the Related Art
Generally, cellular radio communication systems have been developed in preferential consideration of downtown areas having relatively a large amount of telephone traffic. Accordingly, the form of each cell has mainly been designed as a star type. At the center of such a star type cell is provided a base station controller which is linked to a plurality of base stations through dedicated trunk lines of the corresponding base station.
However, due to the continuous development of the mobile radio communication techniques, the number of subscribers of the mobile radio communication networks have been continuously increased. Under the circumstances, the subscribers demand that they achieve call communications anywhere in their country or in specified areas. Practically, the call communications between the subscribers of the mobile radio communication networks have been abruptly increased especially during their travels by trains or by taking highway. Accordingly, researches and efforts to extend the whole service area of the radio communication system with a short construction period and an inexpensive maintenance have been continuously made by industrialists of the radio communication system.
However, if the conventional star type cell is applied to the area in which expressways or railroads are constructed, and in which the traffic amount is relatively small, but the whole service area is relatively large in comparison to a thickly-populated downtown area, the service effectiveness is not so good in contrast with the expenses invested in equipment of the communication system.
Considering the above-described circumstances, if a cellular radio communication system is employed, whereby data communications with a plurality of base stations as well as data communications among the respective base stations can be performed using a single base station controller and a single shared transmission line in a specified area wherein expressways or railroads are constructed, and in which the traffic amount is relatively small, but the whole service area is relatively large in comparison to a thickly-populated downtown area, the expenses of equipping and maintaining the communication system as well as the construction period will be greatly reduced.